CVE-2026-109976 Clevis: clevis: integer underflow in pkcs#11 data socket handler crashes daemon on unbound client connection
An integer underflow in Clevis PKCS#11 handler crashes the daemon on unbound connections, preventing LUKS decryption and causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-109976?
CVE-2026-109976 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 13 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A flaw was found in the clevis PKCS#11 pin. The clevis-pkcs11-afunix-socket-unlock daemon crashes when an AF_UNIX client connects to the data socket without a bound address, due to an integer underflow in the getpeername result handling. This causes a denial of service, preventing LUKS disk decryption from completing during boot.
Weakness: CWE-787
Which versions are affected by CVE-2026-109976?
How do I fix CVE-2026-109976?
Apply the vendor's patch.
Is CVE-2026-109976 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-109976 exists.
Sources
Also known as DEBIAN-CVE-2026-109976, GHSA-vqch-3qxf-26cw, UBUNTU-CVE-2026-109976.